Fire safety systems

ABSTRACT

Conventional water sprinkler heads, mounted in separate rooms, are set off by smoke detectors respectively mounted in the same rooms. A sprinkler head is set off by connecting a resistance wire coil across an electric potential. The heat generated melts the fusible link of the sprinkler head to discharge water therefrom. The coil is resilient to position it on the sprinkler head and is incorporated into a removable probe so that it may be replaced when desired. At a remote nurse&#39;&#39;s station, a set of lights indicates system readiness and also when one or more sprinklers has been set off. Manually operated switches, at the nurse&#39;&#39;s station, permit selected resistance coils to be energized to set off other sprinkler heads. A hallway smoke detector also provides an alarm at the nurse&#39;&#39;s station to alert an attendant to the possible need for remotely actuating selected sprinkler heads or all sprinkler heads by closing a &#39;&#39;&#39;&#39;gang&#39;&#39;&#39;&#39; switch which is also provided.

United States Patent i191 Messerschmidt et al.

[4 1 May 20, 1975 FIRE SAFETY SYSTEMS [76] Inventors: Robert P.Messerschmidt, 9390 Union Cemetary Rd., Loveland,

Ohio 45140; Lloyd D. Montag, 39 Millie Ave, Milford, Ohio 45150 [22]Filed: July 24, 1972 [2]] Appl. No.: 274,817

[52] US. Cl ..169/16, 169/42, 340/418 [51] Int. Cl. G08b 17/06; G08b13/22 [58] Field of Search 340/418,222;169/1 B, 169/] R,20, 16, 37

[56] References Cited UNITED STATES PATENTS 725,827 4/1903 Cowles..l69/37 2,728,904 12/1955 Schafer ..340/409 2,895,125 7/1959 Watts..340/409 3,391,143 6/1964 Renda ..340/4l8 3,726,344 4/1973 Rathman..169/37 Primary Examincr-Th0mas B. Habecker Attorney, Agent, orFirmEdmund S. Lee, III

[5 7] ABSTRACT Conventional water sprinkler heads, mounted in separaterooms, are set off by smoke detectors respectively mounted in the samerooms. A sprinkler head is set off by connecting a resistance wire: coilacross an electric potential. The heat generated melts the fusible linkof the sprinkler head to discharge water therefrom. The coil isresilient to position it on the sprinkler head and is incorporated intoa removable probe so that it may be replaced when desired. At a remotenurse s station, a set of lights indicates system readiness and alsowhen one or more sprinklers has been set off. Manually operatedswitches, at the nurses station, permit selected resistance coils to beenergized to set off other sprinkler heads. A hallway smoke detectoralso provides an alarm at the nurses station to alert an attendant tothe possible need for remotely actuating selected sprinkler heads or allsprinkler heads by closing a gang switch which is also provided.

29 Claims, 6 Drawing Figures 1 I 5 st Lmi PATENTED I 3,884,304 SHEET 2OF 4 FEB E PATENTED W29l975 3,884,304

SHEET 3 OF 4 EM 4o Fusible Material 52 Bonded 53 54 l2\/-/ 54 44a 44bREADY FIRE FIRE SAFETY SYSTEMS The present invention relates toimprovements in fire safety systems.

Various types of fire safety systems have been developed and employedextensively for many years. One of the most widely used systems involvesthe provision of sprinkler heads mounted in the ceiling of a room. Suchsprinkler heads comprise a fusible link which holds a valve closed undernormal conditions. When a fire occurs, the fusible links are melted,allowing the valve to open and water is automatically discharged by thesprinkler heads to extinguish a fire which is presumably locatedbeneath.

Another more recently developed fire safety system, is based on the useof smoke detectors. Such detectors sense an increase in the particulateconcentration in the air, as would be caused by smoke from a fire. Whena given smoke level is reached, an electrical signal is generated by thesmoke detector which actuates an alarm system to alert the residents ofa building or the like that a fire may be in progress.

While such systems have definite value, they do not provide thenecessary level of fire safety which is desirable, if not absolutelynecessary, in convalescent homes and other multi-unit residences forpersons who may be ill or infirm.

The fusible elements employed with sprinkler heads have a relativelylong response time. This is generally satisfactory in protecting abuilding or its inaminate contents from total distruction. However, itis possible for a heat rise, within such a long response time, to reachthe point where a person could be seriously, or even mortally, burned.Different drawbacks are found in conventional smoke detector systems inthat they are no more reliable than the ability of a person to react tothe alarm they provide. Thus an infirm patient would have little or noability to protect himself even if he heard the alarm. Even if anattendant were alerted by such an alarm, his ability to react could beseriously affected if a fire rapidly reached a roaring conflagration.

While the need and desirability for improved fire safety is mostemphasized by the situation in convalescent homes, there are othercircumstances where improvements are also desirable. For example, inprivate residences, hotels, motels, wharehouses, and the like, it isdesirable that a fire safety system give maximum assurance that theentire building or a given area thereof will not reach a stage ofconflagration endangering either occupants or contents.

Accordingly, one objective of the present invention is to provide animproved fire safety system for detecting the potential presence of afire and actuating a sprinkler system before a state of conflagration isreached.

Another object of the invention is to provide an improved fire safetysystem providing a maximum of protection for patients in convalescenthomes or the like.

Another object of the present invention is to attain the above ends in amanner economically compatible with existing fire protection systems.

Another object of the present invention is to provide a unique elementfor shortening the response time for actuation of sprinkler heads infulfillment of the above ends.

In the broader aspects of the invention, these ends are attained by thecombination of a sprinkler head, a

smoke detector, and means responsive to an output signal of the smokedetector for quickly melting the fusible element of the sprinkler headto automatically discharge water therefrom when a given rise in smokedensity occurs.

In another aspect of the invention, means are pro vided for manuallyactuating means for quickly melting the fusible element of a sprinklerhead, thereby discharging water therefrom prior to a fire reaching astage of conflagration.

These features may be combined and employed in a multi-unit building,such as a convalescent home, with smoke detector and sprinkler headcombinations in in dividual rooms. Means can be also provided, at acentral location, such as an attendants station, to give an indicationthat one sprinkler head has discharged. This enables remote actuation ofall of the remaining sprinkler heads or sprinkler heads in selectedrooms by means provided for this purpose. Further, a smoke detector maybe provided in a critical location, such as a hallway, to provide analarm that remote actuation, at the attendants station of some, or all,of the sprinkler heads may be desirable.

More specifically, the fusible element melting means may take the formof an electrical resistance wire which is juxtapositioned relative tothe fusible element, or link, of a conventional sprinkler head. Thisresistance wire is connected across an electrical potential, preferablyof low voltage, which is sufficient to quickly generate a temperaturewhich will melt the fusible element.

The electrical resistance is incorporated, as a separate article ofmanufacture, in a probe which is incor' porated in the electricalcircuits actuated either by the smoke detector or the remote actuationmeans. Preferably, the resistance wire is in the form of a resilientcoil which may be compressed between linkage elements of one type ofsprinkler head to juxtaposition relative to the fusible element. It isalso preferable that the resistance wire be coated with a low meltingpoint dielectric material. This not only insulates the probe from thesprinkler head, but also provides a warning that sprinkler head is aboutto be discharged as the insulation is burnt off when current is passedtherethrough to melt the fusible element. Additionally, the probe may beprovided with means for positively positioning the resistance wirerelative to the fusible element. These means may advantageously beformed as extensions of the dielectric material.

The electrical circuit may economically incorporate lights whichindicate circuit continuity as well as actuation of a sprinkler head.

The above and other related objects and features of the invention willbe apparent from a reading of the following description, with referenceto the accompanying drawings, and the novelty thereof pointed out in theappended claims.

IN THE DRAWINGS:

FIG. 1 is a perspective view illustrating the installation of a tiresafey system, embodying the present invention, in a convalescent home,or the like;

FIG. 2 is a view of a water sprinkler and associated heating elementprobe employed in the present invention;

FIG. 3 is aview similar to FIG. 2 illustrating actuation of the watersprinkler;

FIG. 4 is an enlarged view of the heating element probe employed in thepresent invention;

FIG. 5 is a perspective view of a control box employed herein; and

FIG. 6 is an electrical diagram of the circuit means employed in thepresent invention.

FIG. 1 is a schematic illustration of a portion of a building, such as aconvalescent home, in which the present fire safety system may beincorporated. With more specific reference to a convalescent home, orthe like, a two story building is illustrated showing an upper hallway hfrom which patient rooms may be entered from either side. Specificallyrooms r,,, r,, and r,. are illustrated. From the upper hallway h, astairway s leads to a lower foyer ffrom which other hallways may extendto other patients rooms. A receptionists desk, or nurses station, st isprovided in the foyerf.

Water sprinkler heads 10 and associated heating element probes 12 aremounted on the ceiling of each of the patient rooms r r,, and r and aredesignated by corresponding subscripts. Further, within each of therooms r r,, and r are mounted smoke detectors 14, again identified bycorresponding subscripts. Mounted in the hallway h is a further smokedetector 1411.

As will later be described in greater detail, each sprinkler head 10includes a fusible element which, when melted, releases a valve topermit discharge of water therefrom. Thus, if there should be a fire inany of the rooms, r,,, n, or r which generates sufficient heat to meltthe fusible element, water will be discharged from that particularsprinkler into the room. This, is the conventional function of suchsprinkler heads which is unaffected by the present invention.

Additionally, each smoke detector in a patient room is electricallyconnected, by the illustrated wiring, to the resistance probe within theroom. When the smoke level in the room reaches a pre-determined level,an electrical signal generated by the smoke detector passes currentthrough the electrical probe and causes the fusible element of thesprinkler to melt and discharge water into the room. Thus, theindividual rooms are protected, both from an increase in smoke level,which would indicate a fire, or an incipient fire, as well as from anactual fire which generates, itself, enough heat to melt the fusibleelement. The above description, as well as that immediately following,is functional only and the actual electric current will later bedescribed in detail.

The smoke detectors 14 are additionally connected, by the illustratedwiring, to control boxes 16 which are identified by correspondingsubscripts, at the nurses station st. Each control box, see FIG. 5,includes a pair of lights 18 and 20, which are preferably of differentcolors. The lights 18 indicate that the electrical system for the smokedetector is in a ready condition and capable of actuating the associatedsprinkler head. The other light, 20, indicates a fire condition whereinthe smoke detector has, in fact, actuated the associated electricalprobe and sprinkler head. When a light 20 is lit, the nurse or attendantat station st is alerted to the fact that a fire or potential fireexists in a given room. An audible alarm could also be provided inaddition to or as an alternative to the warning light 20. Dependant uponthe circumstances at the time, the attendant could either check the roominvolved and/or immediately actuate the electrical probes and dischargewater from the sprinklers 10 in adjacent rooms. This latter capabilityis provided by switches 22 which are provided in each of the controlboxes 16. Closing of a switch 22 energizes the associated electricalprobe to discharge water from the sprinkler head to which it isconnected.

The hallway smoke detector 14h may be employed simply as an alarmdevice, being connected to a control box 16h at the nurses station st.The control box 16h, for such purposes would, comprise an alarm light 23and a switch 25. The alarm light 23 would alert an attendant to eithercheck the area involved or to immediately actuate all of the sprinklerheads 10 in the rooms r,,, r,, and r,. by closing switch 25.Alternatively, the hallway smoke detector l4h could also be connected toa resistance probe which would be associated with a hallway sprinklerand function in a fashion similar to the arrangement in the rooms r r,,and r,.

The detailed operation and features of the invention will now bedescribed by next referencing FIG. 2. The sprinkler heads 10 may be ofexisting commercial design. In fact, one of the features of theinvention is that it may be used with such existing sprinkler headswithout modification thereof and thus may be readily incorporated into abuilding with an existing sprinkler system.

The sprinkler head 10, in FIG. 2, includes a casting having an uppernipple portion 24 which is threaded into a mounting plate 26. Themounting plate may be secured by screws 28 to a mounting bracket orother structural element forming a part of the rooms ceiling c. A shortlength of tubing 30 connects the nipple 24 to a T fitting 32 in apressurized Water supply conduit 34. The sprinkler casting alsocomprises a bridle 34 which extends beneath the nipple outlet, asdefined by a valve seat 36. In a state of readiness, discharge of waterfrom the sprinkler head is prevented by a valve member 38 which is heldin place by a pair of lever arms 40 and 42 and a fusible link 44. Thelever arms 40 and 42 have aligned conical tips 46 and 48 whichrespectively engage the valve 38 and the bridle 34. A knife edgeengagement is provided between the lever arms 40 and 42, at 50, in aslightly offset relationship from the aligned points of engagement ofthe conical tips 46 and 48. This provides a leverage arrangementrequiring only a very small force at the ends of the lever arms tomaintain the valve 38 closed against a very substantial water pressurefrom the water conduit 34. The relatively small closing force may thenbe provided by the fusible link 44 even though the fusible material isrelatively weak. The link 44, see also FIG. 4, comprises two plates, 44aand 44b, having a central offset. These plates may be formed of brass orthe like and are joined by the fusible material. The links have a slotand opening in opposite ends, through which the lever arms 40, 42respectively pass. When a fire occurs, the fusible material melts andthe links separate as the lever arms are forced apart and the valve 38released by the force of the pressurized water. The fusible material isa low melting point eutectic which loses its strength relativelysuddenly at a sharply defined temperature. While the response time forrelease of this link is relatively long, at temperatures close to themelting point of the fusible material, the release time is drasticallyreduced when the fusible material is subject to a much highertemperature.

The sprinkler head 10 and its fusible link 44 are merely illustrative.Other sprinkler constructions and fusible elements (not necessarilyeutectic) therefor can be also employed, at least in the broader aspectsof the invention.

Electrical resistance probe 12 is provided to generate a hightemperature for melting the fusible link 44 in response to a signal fromthe associated smoke detector 14 or in response to manual closure ofswitches 22 or 25 at the control box 16 at the nurses station st. Eachelectrical resistance probe 12, referencing also FIG. 4, comprises acoil 52 of nicrome wire or similar electrical resistance materialcommonly used in heating elements. This coil is disposed between thelever arms 40 and 42 in close proximity to the fusible link 44. The coil52 functions as a spring to resiliently maintain itself positionedbetween the arms 40 and 42. The ends of the nicrome wire, forming thecoil 52, are connected to insulated electrical leads 53. Theseconnections, as well as the entire length of wire forming the coil 52,are sheathed within a flexible insulating material 54 such as plastisol,silicone rubber or suitable epoxy resin, having a relatively low meltingpoint. The individual loops of the coil are thus insulated from eachother and all con ductive portions of the probe are insulated from themetal elements of the sprinkler itself. The insulated leads 53 extend toa standard plug-in connector 58. Connector 58 is plugged into a jack 60from which wires (not shown in FIG. 3) extend in a fashion moreexplicitly described in the electrical diagram of FIG. 5 and generallyas indicated in FIG. 1. The probe 12 is thus a replaceable element. Itcan be economically replaced in the event it is energized or founddefective for some reason.

Another feature to be noted is that insulating mate rial 54 is molded,at the opposite ends of the coil 52, to form gripping lugs 61 whichembrace the lever arms 40 and 42. The resilient spring action of thecoil 52 holds it in place and the lugs 61 more positively position itrelative to the link 44.

When a predetermined electrical potential is connected across the coil52, heat is quickly generated to melt the fusible element 44, asevidenced by separation of the plates 44a and 44b, and release the arms40 and 42. When this occurs, the arms 40 and 42 are simply forced fromthe sprinkler, as water pressure displaces the valve 38 away from theend of the nipple 24 and water automatically is discharged therefrom,being spread over a substantial area by a baffle 62 secured to thebottom of the bridle 34. This condition is illustrated in FIG. 3 whereinit will also be seen that the water being sprayed from the sprinkler l0splashes against the heated coil 52 to cool it down and provideassurance that the heated coil itself, will not become a fire hazard.

Another feature in the described arrangement is that when energizingcurrent flows through the coil 52, the insulating material 54 is firstburned or charred away, causing an unpleasant odor which would alert theperson in the room that the sprinkler head was about to discharge. Thisfeature could be employed in various ways. It can serve to alert aperson who is mobile to im' mediately leave the room. It could also bevisually ascertained that there is no immediate danger. In the latterevent, an inactuation switch (not shown) could be employed to shut downthe electrical circuit to the re sistance element and preventunnecessary actuation of the sprinkler, or the same result could beattained by simply pulling the plug 58 from the jack 60.

Referencing next FIG. 6, the electrical circuit employed in the presentinvention is shown in greater detail. The smoke detectors 14 may becommercially available units, well known to those skilled in the art.Such detectors generate an electrical output signal when a predeterminedlevel of smoke, or particulate concentration is sensed. In the presentinstance, this output signal is represented by a coil 64 which isenergized to displace a contactor 66 and close a switch 67. Each of theswitches 67 is connected to one side of a low voltage power supply 68which may be physically located at the nurses station st.

The portions of the electrical circuit which include the room smokedetectors 14a, 14b and each com prise a resistance probe 12 and alarmbulb 20 con nected in parallel and in series with switches 67, 22 andready bulb 18 which are connected in parallel, all of which is connectedacross supply 68.

The portion of the electrical circuit which includes the hallway smokedetector 14h comprises the switch 67h connected in series with the areaalarm bulb 23, across the power supply 68. Also associated therewith, inthe control box 16h is the switch 23 which is a ganged switch connectedfrom one side of the power supply, to provide a separate: seriesconnection with each of the resistance probes 12.

With this arrangement, in the illustrated ready condition of thecircuit, there is current flow through each of the ready bulbs 18, thealarm bulbs 20 and the resistance probes 12. At this point, it will benoted that the resistances of each pair of bulbs 18, 20 is approximatelyequal and that the resistance of the bulb 18 is substantially greaterthan that of the probe coil 52. Thus, the greatest voltage drop will beacross the bulb 18 and it will be brightly illuminated to indicate theready condition. There will be a much lower drop across the coil 52 andthe current flow therethrough will be insufficient to generate enoughheat to either burn its insulating material or melt the fusible link.The current flow through bulb 20 will be insufficient to illuminate it.Should there be an open circuit to or through the probe 12, the bulbs18, 20 would both be illuminated to a reduced brilliance. This wouldindicate that servicing was required.

When one of the room smoke detectors 14a, b, or c, is actuated, itsswitch 67 is closed, say switch 67a. This completes a circuit, shortingout the bulb 18a, through the associated probe coil 52a. With the fullpotential of the power supply 68 connected thereacross, sufficient heatis generated to melt the fusible element in a desired, relatively shorttime period, say in the order of 15 seconds. At the same time,sufficient current flows through the bulb 20a to illuminate it and givea visual signal at the nurses station that the sprinkler in room r, isbeing set off.

At this time, there is an optional capability at the nurses station st,to either set off all sprinklers or sprinklers in selected rooms. To setoff all sprinklers, switch 25 in control box 16h is closed. This connectall of the resistance probes directly across the power supply 68. To setoffthe sprinkler in a given room, the appfpriate switch 22 is closed,connecting the probe for that room directly across the power supply.

While, as pointed out above, the smoke detetQ'r for the hallway besimilarly connected to actuate a Efiii= kler head, in the presentinstance, it is used only 3E an alarm device. Thus, when switch 67hcloses, bulb 25 i illuminated. The attendant at the nurses station canthen make a decision as to what action should be taken and has the sameoptions, as above, to immediately actuate all sprinklers by closingswitch 25 or closing switches 24 for individual rooms, as desired.

One other feature of the circuit which provides additional protection isfound in the provision of a fuse 70 in series with each of the coils 52.The fuses protect against the possibility of fire resulting from anoverload through one of the circuits as a result of a short circuit 1 ina probe 12, particularly when a sprinkler head is discharged.

From the above description, it will be apparent that the presentinvention, particularly within its broader concepts, provides a greatdeal of flexibility which will 1 be apparent to those skilled in theart, and which will result in many modifications, particularly forspecific applications, which depart from the preferred embodimentherein. For example, and not by way of limitation, a properlyconstructed fusible element could be incorporated in the electricalcircuit and current passed therethrough to melt the element to set off asprinkler head. Further dispensersfor fire suppressants other than watercould be employed and in at least some aspects of the invention would beconsidered equivalent to a water sprinkler head. The spirit and scope ofthe present invention is therefor to be derived solely from thefollowing claims.

Having thus described the invention, what is claimed as novel anddesired to be secured by Letters Patent of 3 the United States is:

1. A fire safety system incorporated in an inhabitable structure havinga plurality of rooms or areas, said system including a plurality ofsprinkler heads respectively disposed in said rooms and areas, eachsprinkler head being connected to a source of pressurized fireextinguishing fluid and comprising a valve and means, restrained by afusible element, for holding the valve in a closed position preventingdischarge of said fluid from the sprinkler head,

smoke detectors respectively disposed in said rooms and areas, eachsmoke detector comprising means for producing an output signal inresponse to a given rise in the density of smoke in the rooms and areasin which they are disposed,

resistance means, attachable mounted on said sprinkler heads, formelting the fusible element of 5 each sprinkler head to cause dischargeof the fire extinguishing fluid therefrom,

means for automatically actuating each melting means in response to theoutput signal of a smoke detector adjacent thereto,

a control station remote from at least some of the rooms and areas inwhich the sprinkler heads are disposed,

an alarm, disposed at said control station, actuated in response to theoutput signal of one of said smoke detectors which is disposed in acritical room or area and is independent of the fusible element meltingmeans,

separate alarms, disposed at said control station,

means, disposed at said control station, for manually and selectivelyactuating the fusible element melting means upon being alerted by saidalarms, and

means, disposed at said control station and connected to each meltingmeans, for indicating that the fusible element melting means are in astate of operativeness to be actuated by either the automatic or manualactuating means therefor.

2. A fire safety system as in claim 1 wherein the fusible elementmelting means comprise electrical resistance wires respectivelyjuxtaposed relative to the fusible elements of the sprinkler heads andan electrical potential across which the resistance wires may beconnected,

the means for automatically actuating the fusible element melting meansinclude normally open switches, respectively connected in series withthe resistance wires, which are closed to connect the respectiveresistance wires across said electrical potential,

the manual means for actuating the fusible element melting meanscomprise switches, disposed at said control station, respectivelyconnected in parallel with said automatic switches the means forindicating that the fusible element melting means are in a state ofoperativeness, comprise ready light bulbs respectively connected inparallel with said switches,

the separate alarms comprise alarm light bulbs respectively connected inparallel across the resistance wires, and

the resistance of said ready light bulbs is substantially greater thanthat of the resistance wires and the resistance of the alarm light bulbsis at least approximately as great as that of said ready light bulbs.

3. A fire safety system incorporated in an inhabitable structure havinga plurality of rooms or areas, said system including a plurality ofsprinkler heads respectively disposed in said rooms and areas, eachsprinkler being connected to a source of pressurized fire extinguishingfluid and including a valve, a pair of lever arms which have generallyaligned portions for maintaining the valve in a closed position andgenerally parallel portions projecting outwardly, and a fusible elementrestraining said parallel portions from separation as the alignedportions maintain the valve in its closed position to prevent dischargeof said fluid from the sprinkler head,

smoke detectors respectively disposed in said rooms and areas, eachsmoke detector comprising means for producing an output signal inresponse to a given rise in the density of smoke in the rooms and areasin which they are disposed, resistance element attachably mounted on theparallel portions ,of the lever arms of each sprinkler head injuxtaposition to the fusible element thereof, means for automaticallyconnecting each resistance element across an electrical potential inresponse to the output signal of a smoke detector adjacent thereto, tomelt the juxtaposed fusible element independently of the ambienttemperature thereof and thus discharge fire extinguishing fluid fromthat sprinkler head,

a control station remote from at least some of the rooms and areas inwhich the sprinkler heads are disposed,

an alarm, disposed at said control station, actuated in response to theoutput signal of one of said smoke detectors, and

means, disposed at said control station, for manually and selectivelyconnecting said resistance elements across an electrical potential tomelt the fusible elements juxtaposed thereto and discharge fireextinguishing fluid from sprinkler heads in selected rooms and areas.

4. A fire safety system comprising a sprinkler head connected to asource of pressurized fire extinguishing fluid and including a valve, apair of lever arms which have generally aligned portions for maintainingthe valve in a closed position and generally parallel portionsprojecting outwardly, and a fusible element restraining said parallelportions from separation as the aligned portions maintain the valve inits closed position to prevent discharge of said fluid from thesprinkler head,

a resistance element attachably mounted on the parallel portions of saidlever arms in juxtaposition to said fusible element, and

means for connecting said resistance element across an electricalpotential to melt said fusible element independently of the ambienttemperature of the element and thus discharge fire extinguishing fluidfrom the sprinkler head.

'5. A fire safety system as in claim 4 wherein the resistance elementcomprises a resistance wire which is resiliently and axially deflectableand has a length greater than the distance between the parallel portionsof the lever arms and further includes lugs, at opposite ends of theaxial length of the resistance wire, for embracing the sides of theparallel portions of the lever arms,

whereby the resistance element may be juxtaposed relative to the fusibleelement of the sprinkler head by compressing the axial length of theresistance wire and positioning the lugs to embrace the sides of saidparallel lever portions so that upon release the resistance element issecurely held in place.

6. A fire safety system as in claim 4 wherein the resistance element isin the form of coiled, resistance wire, compression spring having anaxial length greater than the distance between the parallel portions ofthe lever arms, which resistance wire spring, when compressed betweenthe parallel lever arm portions is resiliently held in juxtapositionrelative to the fusible element.

7. A fire safety system as in claim 6 wherein the resistance wire springis sheathed within a flexible, low melting point, dielectric materialwhich has integrally formed lugs at the opposite ends of the resistancewire spring, which lugs embrace the sides of the parallel lever armportions to more securely position the resistance element thereon.

8. A fire safety system as in claim 4 which further includes adetachable electrical connector for incorporation into the means forconnecting the resistance element across an electrical potential, and

insulated, flexible electrical leads connecting opposite ends of theresistance element to said connector, thereby forming a probe comprisingthe resistance" element, the connector and the connecting leads.

1. A fire safety system comprising: a water sprinkler head connected to a source of pressurized water, and including a valve and means, restrained by a fusible element, for holding said valve in a closed position preventing discharge of water from said sprinkler, a smoke detector including means for producing an output signal in response to a given rise in smoke density, means responsive to said output signal for generating heat sufficient to melt said fusible element, thereby releasing said valve and discharging water from said sprinkler.
 2. A fire safety system as in claim 1 wherein the heat generating means comprise an electrical resistance wire juxtapositioned relative to said fusible element and means for connecting said electrical resistance element across an electrical potential sufficient to generate a predetermined heat level.
 3. A fire safety system as in claim 1 further comprising manually operated means for independently actuating the heat generating means.
 4. A fire safety system as in claim 1 wherein a plurality of said sprinkler heads are provided a plurality of said smoke detectors are provided, and additional means, responsive to the output signal of each additional smoke detector are provided for generating heat sufficient to melt the fusible element of a given sprinkler head thereby discharging water from said sprinkler head.
 5. A fire safety system as in claim 4 further comprising manually operated means for separately activating selected heat generating means and manually operated means for manually actuating all of said heat generating means.
 6. A fire safety system as in claim 5 wherein each of the heat generating means comprise an electrical resistance wire juxtapositioned relative to each of fusible element and means for connecting said electrical resistance element across an electrical potential sufficient to generate a predetermined heat level.
 7. A fire safety system as in claim 6 in combination with a building comprising a plurality of rooms and a common area and further wherein a smoke detector and a water sprinkler head combination are respectively mounted in separate rooms thereof, the resistance element of the water sprinkler in one room is connected across the electrical potential in response to the output signal of the smoke detector in that room, and further comprising a further said smoke detector mounted in said common area and means, responsive to said further smoke detector, for providing an alarm for alerting an attendant as to the possible need for operating said manually operated means.
 8. A fire safety system as in claim 7 wherein the manually operated means and the means for providing an alarm are disposed in a common, remote location.
 9. A fire safety system as in claim 4 in combination with a building comprising a plurality of rooms and further wherein a smoke detector and water sprinkler head combination are respectively mounted in separate rooms thereof.
 10. A fire safety system as in claim 9 wherein each of the heat generating means comprise electrical resistance wires respectively juxapositioned relative to the fusible elements of each sprinkler head and an electrical potential across which said resistance wires are adapted to be connected, and the means responsive to the output signal of a smoke detector in a room connect the resistance element of the water sprinkler in that room across the electrical potential.
 11. A fire safety system as in claim 10 wherein the means responsive to said smoke detectors include normally open switches respectively connected in series with said resistance wires across the electrical potential.
 12. A fire safety system as in claim 11 wherein ''''ready'''' light bulbs are respectively connected in parallel across said switches and ''''alarm'''' light bulbs are connected in parallel with said resistance wire and further wherein, the resistance of said ''''ready'''' light bulbs is substantially greater than the resistance of said resistance wires and further wherein the resistance of the ''''alarm'''' light bulbs is at least approximately as great as that of said ''''ready'''' light bulbs.
 13. A fire safety system as in claim 12 wherein said light bulbs are mounted at a common, remote station and further wherein manually operable switches are respectively mounted in parallel with the parallel connected ''''ready'''' light bulbs and switches, said manually operated switches also being mounted at said common, remote stations.
 14. A fire safety system as in claim 13 wherein a hallway, or the like, is adjacent said separate rooms and a further, said smoke detector is mounted in said hallway means responsive to the output signal of said hallway smoke detector provide an alarm signal at said common, remote station and a normally open, manually operable switch adjacent said hallway alarm is connected in series with a plurality of said resistance wires, across said electrical potential, whereby all of said resistance wires can be connected across said electrical potential in response to the hallway alarm.
 15. A fire safety system as in claim 10 wherein each resistance wire is incorporated into a probe removably connected into the electrical connections therefor.
 16. A fire safety system as in claim 15 wherein the resistance wire is in the form of a resilient coil and is covered with insulation material.
 17. A fire safety system as in claim 16 wherein each sprinkler head has opposed arms adjacent the fusible element thereof and positioning means are provided at the opposite ends of said coil to hold said coil in juxtaposition with said fusible element.
 18. A fire safety system as in claim 2 wherein the electrical resistance wire is incorporated into a probe removably connected with the means connecting the resistance wire across the electrical potential.
 19. A fire safety system as in claim 2 wherein the electrical resistance wire is in the form of a resilient coil and is covered with flexible, low melting point dielectric material.
 20. A fire safety system as in claim 19 wherein said electrical resistance probe includes means for positioning said coil in juxtaposition with said fusible element.
 21. A probe for use in a fire safety system, said probe comprising an electrical resistance wire adapted to be juxtapositioned relative to a fusible element which is to be melted to set off a sprinkler head, and electrical leads connected to the opposite ends of said coil and removably connectable into an electrical circuit for passing current through the resistance wire to generate heat sufficient to quickly melt the fusible element.
 22. A probe as in claim 21 wherein the electrical resistance wire is in the form of a resilient coil.
 23. A probe as in claim 22 wherein the electrical resistance wire, including the coil, is covered with a flexible, low melting point dielectric material having a distinctive odor when heated to an elevated temperature.
 24. A probe as in claim 23 wherein the probe includes means for gripping the water sprinkler head and position the resistance wire coil in juxtaposition to the fusible element thereof.
 25. A probe as in claim 24 wherein the gripping means are integrally formed of said insulating dielectric material and comprise lugs at the opposite ends of said coil.
 26. A fire safety system comprising a water sprinkler head connected to a source of pressurized water, and including a valve and means, restrained by a fusible element, for holding said valve in a closed position preventing discharge of water from said sprinkler, and electrical resistance means for generating heat suffIcient to melt said fusible element, thereby releasing said valve and discharging water from said sprinkler.
 27. A fire safety system as in claim 25 wherein the heat generating means comprise an electrical resistance wire juxtapositioned relative to said fusible element and manually operable means are provided for connecting said electrical resistance element across an electrical potential sufficient to generate a predetermined heat level.
 28. A fire safety system as in claim 27 wherein the electrical resistance wire is in the form of a resilient coil and is covered with a flexible, low melting point dielectrical material.
 29. A fire safety system as in claim 28 wherein the electrical resistance wire is incorporated into a probe removably connected with the electrical connections to said electrical potential. 